When I run the following I get what is obviously a spurious straight line
connecting (-100,0) and (300,400*.7). How do I get rid of that line?
{{-100,0},{0,-100},{100,-200*.9},{200,-300*.8},{300,-400*.7},{-100,0},{0,100
},{100,200*.9},{200,300*.8},{300,400*.7}}
ListPlot[%, PlotJoined->True]
Jeff